Two-Particle Correlations and B⁰bar{B}⁰ Mixing

We study the EPR correlation implied by the entangled wavefunction of the $B^0\bar{B}^0$ pair created by the $\Upsilon $(4S) resonance. The analysis uses the basis provided by the mass eigenstates $B_1,B_2$ rather than the flavour states $B^0, \bar{B}^0$. Data on the inclusive dilepton charge ratio are close to the expectation of quantum mechanics, but nearly 8 standard deviations away from that of complete decoherence.